Passwords
PDF passwords: protect, unlock and change a PDF password
By DeckleUpdated
To put a password on a PDF, open Password protect PDF, type the password twice and choose Protect this PDF. To take a password off a PDF you can open, use Unlock PDF, enter the current password and choose Remove the password. Both tools save a new copy in your browser and leave the original file as it was.
Three different privacy tasks
Password
Controls access
Metadata
Document properties
Redaction
Selected page content
Choose the change; inspect the saved copy
Find the right guide
| You want to | Read |
|---|---|
| Make a PDF ask for a password before it opens | How to password protect a PDF |
| Remove a password you know | How to remove a password from a PDF |
| Swap an old password for a new one | How to change the password on a PDF |
| Open a protected PDF someone sent you | How to open a password-protected PDF |
| Pick a password that is hard to guess | How to choose a strong password for a PDF |
| Fix a password that is not accepted | Why is my PDF password not working? |
| Get into a PDF whose password you have lost | Can you unlock a PDF without the password? |
| Edit or print a PDF that opens but is locked | Why a PDF opens but cannot be edited |
| Understand open passwords and permissions | Open password vs permissions password |
| Know what AES-256 protects | What AES-256 PDF encryption protects |
Two kinds of PDF password
The PDF format defines two passwords, and they do different jobs.
- Open password (also called the user or document open password). The reader asks for it before showing any page. Without it, the file cannot be read.
- Permissions password (also called the owner password). The file opens for anyone, but the reader blocks actions such as printing, copying text or editing until this password is entered.
Deckle's Password protect PDF sets an open password and uses the same value as the owner password, the one that grants full access. It has no settings for printing or editing restrictions. If you need those, see open password vs permissions password for the apps that offer them.
What each Deckle tool does
| Password protect PDF | Unlock PDF | |
|---|---|---|
| Input | One PDF without a password | One PDF with a password or restrictions |
| You enter | A new password, twice | The current password, or nothing for restriction-only files |
| Button | Protect this PDF | Remove the password |
| Output name | The original name with "(protected)" | The original name with "(unlocked)" |
| Encryption | AES-256 | None |
| Check before the result appears | The copy refuses an empty password and opens with yours | The copy opens without a password and keeps every page |
Both tools take one file per run. Pages, page sizes and text stay as they were. The encryption changes, and both tools write "Deckle" into the Producer property.
What a password does not do
A password controls who can open the file. Once someone opens it, they can read every page, and they can save or forward a copy if their reader allows it. A password also does not:
- remove text from the page. To take a name or number out for good, the information has to be redacted, not locked.
- remove hidden properties such as the author or editing app. Use Remove PDF metadata before you protect the file.
- prove who sent the document. That is the job of a digital signature; see password protection or a digital signature.
Tips
- Clean the file before you lock it. Remove metadata and unwanted pages first, because the protected copy has to be unlocked before other tools can change it.
- Send the password separately. Put the file in one message and the password in another channel, such as a phone call. See how to share a password-protected PDF.
- Store the password before you send the file. Deckle has no copy of it, and there is no reset.
- Keep the unprotected original only if you need it. Deckle never changes it, so delete it yourself if it should not stay on your device.
Frequently asked questions
Is the PDF uploaded when I add or remove a password?
No. Deckle encrypts and decrypts the file in your browser. The password is not stored, put in a link or written into the result record.
Can Deckle recover a forgotten PDF password?
No. Unlock PDF needs the correct password. It does not guess or crack passwords. Ask the person who protected the file for the password or an unprotected copy.
Can I protect several PDFs at once?
Not in one run. Protect each file in turn, or combine them with Merge PDFs first and protect the merged file.
Which encryption does Deckle use?
AES-256 when it protects a file. Unlock PDF opens files that use standard password encryption, including older RC4 files and current AES files.
Related tools
- Password protect PDF to add an open password
- Unlock PDF to remove a password you know
- Remove PDF metadata to clear document properties before you share